Título:	Balanço de energia e fluxo de carbono em uma área de cerrado que sofreu queima acidental
Autor(es):	Maia, Jair Max Furtunato
Orientador(es):	Miranda, Heloisa Sinátora
Assunto:	Cerrados - queimada Reserva Ecológica do IBGE Biomassa vegetal Cerrados - vegetação Fluxo de carbono
Data de publicação:	20-Mai-2020
Data de defesa:	30-Abr-2003
Referência:	MAIA, Jair Max Furtunato. Balanço de energia e fluxo de carbono em uma área de cerrado que sofreu queima acidental. 2003. xiii, 75 f., il. Tese (Doutorado em Ecologia)—Universidade de Brasília, Brasília, 2003.
Abstract:	Although it is known that the vegetation of the Cerrado is for atmosphere a CO2 sink during the rainy season and a CO2 source in the end of the dry season, there are few studies reported on the effect of lire these effects, iliis study was conducted at in the IBGE Ecological Reserve, close to Brasília, DF, with the objective to measure the recovery of phytomass and the evapo-transpiration rates and CO2 and water vapor fluxes in a area of 37,3 ha that suffered an accidental burning in August 1999. The recovery of aerial phytomass, the vegetal cover and of the CO2, water vapor and radiation fluxes, by the eddy covariance technique were monitored from August 2000 to October 2002. The index of tree cover was of 11% in the dry season and 18% in the wet season. 'The biomass composition of the low level presented a reduction in green leaves, from 234 gm‘2 in April 2000 to 122 gin'2 in April 2002. However, live branches grass amounted to 120 gm'2 each during this period. The seasonality was strong in every year, with reduction of up to 73 % in the biomass of the low layer in the dry station. A gradual increase in necromass of all of the low layer components was observed with an increase of up to 400% of the initial values. The exception is for the dead branches which showed value of 100 gm'2. The phylosociological survey of 2001 showed an aerial biomass of 9.16 tha'1 for woody plants diameter > 2.0 cm and 0.02 tluf1 for tree individuals with diameter < 2.0 cm with a total basal area of 121.6 n rh a'1 and total volume of 2,443.7 m3ha'1. 'Hie slope of the energy balance equation during the three years for the area was not significantly different. The variation in the components of the energy balance equation for the rainy season was: 451 Wnf2 to 716 Win'2 for solar radiation (St); 240 Wm'2 to 433 Wm"2 for liquid radiation (Rn); 111 W nf2 to 216 Wnf2 for sensible heat (H) and 120 W n f2 to 189 W in'2 for latent heat (À.H). In the dry season (June - September) the values varied from 394 Wm'2 to 742 Win'2 for St; 187 Wnf2 to 433 W nf2 to Rn; 119 Wm"2 to 262 Wm'2 tor H and 74 Win'2 to 111 Wm'2 (br À.K. About 45% of the radiation balance was used in the evapotranspiration process during the rainy season (XE/Rn = 0,45). The values of fluxes in the ground (g) varied from 17 Wm 2 in the rainy season to 14 wm‘~ in the dry season. The slope of the energy balance, plot (Rn-G) versus (1I-Â.E), for the three years, was 0,93. The sensible heat represented 46% of Rn during this period. The stomata resistance (rs) varied from 158 sm"1 to 278 snT1 in the wet season and 391 sm'1 to 259 sm'1 in the diy season. The values of maximum photosyntheses (Pmax) had varied from 5,9 pmolm'V1 in the dry season to 10,7 pmol.m^.s'1 in the wet season. The maximum values of carbon absorption was around of 11:00 AM and 02:00 PM, with a gradual reduction in maximums absorption to 3,87 pmolm'V1 and 6,12 pmolm'V1 in the rainy and beginning and middle of the dry season, when the area functioned as a carbon sink, with the maximum of assimilation (-484.2 pmolm'V1) and emission (304,8 mmolm'V’) in December. During August and September, when the area functioned as carbon source for the atmosphere, the maximum value of absorption was -3,46 pmolm'V1 and -3,33 pmoIm'V1, respectively. It was not possible to calculate with precision the total or emission of carton to 2000, but the estimate for 2001 were 1,746 kg Cha'1 and 214,8 kg Cha*1 and for 2002 was 238,4 kg Cha'1 and 1,419.7 kg Cha'1 of emission and accumulation respectively.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB)
Informações adicionais:	Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, 2003.
Programa de pós-graduação:	Programa de Pós-Graduação em Ecologia
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

Os itens no repositório estão protegidos por copyright, com todos os direitos reservados, salvo quando é indicado o contrário.